One thing I've discovered in writing nearly a dozen years worth of Focus On Nature columns is that the annual cycles of nature coincide with an annual recycling of nature questions.

Other questions deal with everything from where to find outdoor photography courses to the location of specific points of interest mentioned previously on these pages. Here are a few questions already fielded at this desk via phone or note. Some of them have been asked before, as this first entry.

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From an Allentown woman: "I have a crazy bird in my yard. It's a robin and every day it bangs against the window of my laundry room. Sometimes it flies against the glass so hard I think it's going to break its neck. Other times it just sits on the window sill and jumps at the glass. It's making a real mess of the window. Did you ever hear of a bird doing this before?"

Love is in the air and spring brings an instinctive desire for male birds to establish territories. The males handle this part of the annual courting and nesting ritual, attempting to establish property boundaries by audible signposts - specifically singing. When an intruder of the same species and sex enters the boundary, the squatter attempts to drive him off. Reflections in windows or car mirrors confuse the squatters and attempts are made to drive the "intruders" away. This is typically done by rushing the reflection, often with such vehemence that the bird bounces off the glass and lies dazed on the ground. Somehow, no matter if it's a robin, cardinal, mockingbird or some other species, the plight is never fully understood and the routine may go on for several weeks before a truce is called.

The best advice is to grin and bear it - even though your spring housecleaning chores may be slightly upset by the mess created on the panes.

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From a Bucks County woman: "This is our first spring in our new home in upper Bucks County. Since last Sunday we've been hearing birds in the morning and again just before it gets dark. They have a high-pitched call; more a chirp than a song. The calls come from a swampy, grassy area near a stream. One night my husband and I tried to locate them but we couldn't find any. Can you tell us what kind of birds they might be?"

Methinks that your "birds" are actually frogs; spring peepers to be precise. It often astounds people who've not previously heard the piercing call of the tiny spring peeper that the song emanates from a little amphibian no bigger than the end of one's thumb. By inflating their vocal sacs they can squeeze out noise that can be heard upto a mile away on otherwise quiet spring evenings. In concert, their mass singings have been likened to "the sounds of creatures from another planet." Many people also mistake their calls for that of insects, often crickets. Chances are you'll have difficulty finding the frogs as any nearby movements or the shining of a flashlight immediately quell them. But stay long enough, stand quietly, and you may see one perched on a pussy willow or cattail, sending out calls to entice mates to a marsh pool or roadside ditch where the matings take place.

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From a Trexlertown man: "Every day on my way to work I pass the Little Lehigh in the Trexlertown area. In the past few days I've seen some large cranes or herons along the water. They're all gray in color. Isn't this kind of bird rare in this area?"

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A crane would, indeed, be rare. But chances are you're seeing great blue herons which do not nest in the Lehigh Valley but can be seen here in practically every month of the year - except during the coldest days of winter. Spring and fall bring the migrants and they'll utilize the shorelines of streams, rivers, ponds and lakes - wherever their prey of small fish, tadpoles, crayfish and other animal life, including an occasional field mouse, can be found. My son and I saw three of them in a small woodland stream in southern Lehigh County last week. Keep your eyes peeled for these statuesque birds that stand four feet tall and show wingspreads of seven feet in flight.

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From a Bethlehem man: "A friend of mine swears that he saw a dead coyote along Route 33 near Stockertown a few weeks ago. As far as I know, coyotes only live in the West. Is it possible this was a coyote or was it a German shepherd dog, as I think it was.?"

Chances are your friend was right. Coyotes moved into Pennsylvania at least 20 years ago and in the past decade have become common in the Poconos. The last few years have seen them spread their range into the Lehigh Valley with substantiated records of them having been seen or trapped in southern Lehigh County near Limeport, at and near the A-B-E Airport, and along the Blue Mountain. This is Pennsylvania's newest predator that, because of its high reproductive rate, may already be inhabiting practically every county of the commonwealth but definitely the northern tier woodlands.